Small Egg?

[Cpt. Nemo]

Here is an eggshell of the French Miocene. We would say a small egg of a centimeter ( as an egg of hummingbird for example). Have you ever seen this kind of thing?

[glacialerratic]

Reminds me of a lizard egg. Nice find!

[Cpt. Nemo]

Hello,
Effectively, the size reminds the lizard. But the eggshell of a lizard is supple, to my knowledge.

[Auspex]

Ten years ago, I would have said that hummingbirds were known only from the new world, but fossils were found in 30 MYO deposits in southern Germany.

That said, it is difficult for me to extrapolate the original shape of this egg; it almost seems to be too elongate to be from a hummingbird, and there is no other bird that could have laid such a tiny egg (1 cm). Also, some irregularities in the surface suggest that it may not have been a brittle shell. Short of microscopic analysis of the shell's structure, I lean toward it as being from a lizard.

[Cpt. Nemo]

Effectively: today hummingbirds are only in North America, but in the Miocene one there found that in Europe.

The shell(misprint) is similar in thickness and in color to those of bigger birds than I found in the same sector. I am going to try to make abetter photo to see thepossible irregularities of the misprint.

[Cpt. Nemo]

Some other photos:

[Auspex]

A typical small passerine's egg is 2.22cm X 1.59cm; is your 1cm measurement an approximation of the egg unbroken, of is it the length of the specimen as-is?

[Cpt. Nemo]

Is the length of the specimen as-is.
But seen the shape, I do not think whether it is much longer integer.

[painshill]

Had you considered it might be a rail egg (Rallidae)? Those are reported from the Miocene of France and rails can be quite small (modern species down to about 12cm for the bird itself). I have seen Palaeoaramides and Paraortygometra reported for the French Late Oligocene/Early Miocene - Late Miocene for example. There is one species in particular reported from France - Palaeoaramides minutus - which I assume from the name was one of the tiny species.

[Auspex]

Rails lay big eggs for the size of the bird (precocial young, you know; hatching at an advanced state of development). Even the smallest rail would have much larger eggs than this.

[Cpt. Nemo]

The idea is interesting. The environment can correspond: banks of lakes.
But as Auspex I think that their eggs are bigger.

However I do not know the species Palaeoaramides minutus which is maybe smaller?

[painshill]

The idea is interesting. The environment can correspond: banks of lakes.

But as Auspex I think that their eggs are bigger.

However I do not know the species Palaeoaramides minutus which is maybe smaller?

I have no idea either. I believe P. christyi is the largest of the genus and P. minutus is the smallest (so far). Lengths for the tarsometatarsi of the two species from incomplete specimens in the BMNH are 60mm and 25mm respectively but I don’t know how that relates to bird size in rails, never mind egg size!

Edited February 22, 2013 by painshill

[glacialerratic]

the eggshell of a lizard is supple, to my knowledge.

Would this show as a thinner shell?

Best wishes on narrowing down the ID!

[Cpt. Nemo]

To my knowledge we do not know fossils of eggs of lizard about supple misprint. Those of Bouxwiller would not be there.

And here the misprint looks like completely (thickness,color) to those of the other eggs of bigger birds found in the same place.